An ISX Manager will have slow access to devices on the private network (APC LAN) if the ISX Manager is configured with an incorrect primary and secondary DNS server.

During the HTTP connection to the private side device, it uses a SOCKS proxy. That proxy performs a DNS lookup. If the primary and secondary DNS servers configured in ISX Manager are invalid (meaning the address does not respond to a ping), the connection will timeout. That timeout is 10 seconds. ISX Manager tries once for primary, once for secondary.

The HTTP protocol tries once without authentication, and then again with authentication, leading to a 40 second delay from when the user tried to launch to the device. During this time the user will see a blank window appear as the Manager attempts to log into the device.

Resolution

Verify your DNS configuration. If the configured DNS servers IP's respond to a ping (even if they are not DNS servers) the connection will fail immediately, thus not causing the slow private side access.